Adapter for PCI-x to PCIe ??

[pavanbabut]

Hi, Does anyone know if there are any adapters available to install a PCI-X 64bit (133MHz) card on a PCIex8 slot which runs at x4 bus speed?? I know that there are interchangeable adapters available to install boards of PCIe (x1,x2,x4,x8,x16). But since a PCI-X 64bit 133MHz runs at the same speed as PCIex4 speed, I wonder if there are any adapters of this kind... :~ -Pavan

[Dan Neely]

You're somewhat confused on terminology at a minimum. The PCIe bus runs at a flat 100hmz, 1x, 2x, etc refer to how wide the bus is, a 1x PCIe card runs at the same speed as a 16x card, it just has higher bandwidth. That said, while a PCIe4x bus might have the same bandwidth as a PCIX133-64 bus (I'm taking your word for it), the signaling details are different, at a minimum 4 PCI-X 64bit words would need converted into 3 PCIe words before being sent onto the PCIe bus. This would require a processor of some sort to do the conversions in near realtime, and would likely still result in some degree of increased bus latency. You'd also have the problem of the card in the adaptor being raised higher than the other cards and not being able to screw into the backplate properly, so I very much doubt any such device would exist.

-- Rules of thumb should not be taken for the whole hand.